Capstan



March 18, 1958 ojE. BEVER v 2,826,939

CAPSTAN Filed Aug. 2, 1954 .5 Sheets-Sheet 1 ATTORNEY o. E. DEVER2,826,939

March 18, 1958 cAPsTAN Filed Aug. 2, 1954 3. Sheets-Sheet 2 I HL.

INVENTOR. E VE@ o. E. :.JEVER 2,826,939

l cAPsTAN March 18, 1958 3 Sheets-Shree?l 3 Filed Aug. 2, 1954 INVENTOR.0770 DE aff@ United States Patent O cAPsTAN Otto E. Dever, Burbank,Calif. Application August 2, 1954, serial No. 447,111

10 claims. (ci. 'I4-801) This invention relates to a capstanconstruction and, while adapted for many different uses, Vis moreparticularlyl adapted to move cargo in airplanes and also to move heavyobjects in the open field. Accordingly, this inven tion contemplates oneform of the invention that is, with easy facility, connected to thefloor of a cargo airplane, as by conventional fittings provided in saidfloor. The invention also contemplates a second form that can beconnected to any fixed point or object such as a tree or stump, or alarge boulder, and thus used in the open field.

An object of the present invention is to provide a power-driven capstanthat embodies novel power advantage features which enable the readyhandling by the capstan of heavy objects.

Another object of the invention is to provide a motordriven capstan thatembodies novel power gearing between the motor and drum of the capstanwhich results in a power advantage for said drum.

A further object of the invention is to provide novel and improved meansto separably connect the capstan in operative position.

The invention also has for its objects to provide such means that arepositive in operation, convenient in use, easily installed ina workingposition and easily disconnected therefrom, economical of manufacture,relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novelcombinations and arrangements of parts, which will more fully appear inthe course of the following description. However, the drawings merelyshow and the following description merely describes, preferredembodiments of the present invention, which are given by way ofillustration or example only.

In the drawings, like reference characters designate similar parts inthe several views.

Fig. 1 is a plan sectional 'view of a capstan constructed according tothe invention, said view being taken on line 1-1 of Fig. 2.

Fig. 2 is a vertical elevational View, partly in section, as taken online 2-2 of Fig. 1.

Fig. 3 is a vertical and fragmentary elevational and sectional view astaken on line. 3-3 of Fig. 1.

Fig. 4 is a plan view of a modification.

Fig. 5 is a side elevational view in quarter section of the capstanshown in Fig. 4.

The present capstan comprises a base 10, a revoluble drum 11 disposedabove said base, an electric motor 12 within said drum, power-advantagegearing 13 carried partly by the base, partly by the drum, and partly bythe shaft 14 of said motor, and a one-way clutch 15 to obviate backup orbacklash of the mechanism. The form of Figs. 1, 2 and 3 embodies means16 in the base to effect separable connection to tie-down fittingsprovided asin the floor of a cargo airplane. The form of Figs. 4 and 5provides said base with a lateral extension 17 adapting the base andcapstan to be rendered captive.

In the form illustrated in Figs. vl, 2 and 3, the base has a'generallyH-shaped form in which the base legs 2,826,939 'Patented Mar. 1s, 195sICC 20 are connected by an integral cross part 21. In the latter part,the base is provided with a circular hub 22 that has a closed bottom 23,the hub 22 having formed. therein a circular inner seat 24 adjacent saidbottom and. a somewhat larger seat 25 in the upper portion thereof..Although formed as a separate member, a support 26 isy seated in seat 25and is securely fastened to hub 22, as.' by boltsV 27. Said supportextends substantially above: the upper face of base 10 and is finishedas a circular boss: 28 that has a central axis coincidental to thecenter off seat 24.

The drum 11 comprises a vertically disposed portion: 29 that is providedwith a conically tapered outer surface-v 30 that is larger at the topthan at the bottom. From the: bottom, said portion 29 is outwardly anddownwardly? flared at 31 and then extended as an enlarged horizontalplate part 32 that terminates in a downwardly directed peripheral skirtor flange 33. The upper end of the drunr is closed by a cap or cover 34awhich may comprise a separate member fixedly bolted to the upper edge ofthe drum portion 29. Adjacent its lower end, the portion 29 is providedwith an inreaching transverse flange 34 that has a central opening.

Inwardly of support 26 and affixed to said flange 34, as by bolts 35,there is provided a hub 36 that is coaxial with support 26. Suitablevertically spaced anti-friction bearings 37 mount hub 36 within the boss28 of said sup port and, therefore, rotationally mount the drum 11 abovebase 10. It will be noted that bearings 37 are large diametrally and,therefore, greatly resist torsion load forces that are applied to thedrum and transmit the same, through the relatively large and stable boss28 of the support 26 to the base 10.

The electric motor 12 has its stator or field 38 affixed; to the drumand the usual armature or rotor, within the.; field, afxed to shaft 14.Consequently, said drum and; shaft are relatively rotational.

The gearing 13 comprises an internal or ring gear 392 disposed in seat24 and secured to hub 22 as by bolts 40;; a second internal or ring gear41 having a slightly greater pitch diameter than gear 39, affixed to hub36 and disposed above and immediately adjacent to gear 39; a sun gear 42affixed to or formed integrally on shaft 14; a set of twin planetarygears (only one of which is shown in the drawings) and formed with agear 43 intermeshing with fixed ring gear 39 and sun gear 42 and with aslightly larger gear 44 meshing with ring gear 41; and a freelyrotational ca'ge 45 mounting said twin planetary gears 43-44.

The upper end of shaft 14 is engaged in a radial bearing (not shown)provided in the drum cap 34 and the lower end is in thrust engagementwith a plate 46 fitted to the center of cage 45 and, in turn, supportedon a thrust screw 47 adjustably carried by the bottom wall 23 of hub 22.A radial anti-friction bearing 48 is interposed between an intermediatepart of said shaft and both the drum ange 34 and hub 36. The upper endof shaft 14 constitutes an armature shaft for motor 12, and may beformed separately from the lower portion, and be connected by suitablesplines. Thus, the armaturemounting end of said shaft may assume anyux-induced endwise position without affecting the gear-provided end.

The clutch 15 is shown as having one part 49 carried by shaft 14 and theother part 50 formed on the hub 36. The clutch is of the usualone-direction type in which part 49 rotates freely in part 50, in onedirection, and has:

turned in the opposite direction.

The means 16 is provided in each of the base legs 20 and is shown ascomprising slidable blocks 51 in guides 52 provided in said legs andmoved endwise by turn-JV buckle means 53. Said blocksSl carry flangedmembers,

54 .that are adapted to effect connection with floor ttings, ashereinbefore indicated.

Since both the stator and rotor of the motor 12 rotate with relation tobase 10, electric power is brought from the base to the drum by brushmeans 55. A switch 56 in said base is provided to control operation ofthe'motor.

In operation, the shaft 14 is rotated, for instance in the directionshown by the arrow 57, causing rotation of the twin gears in thedirection of arrow 5J. This latter rotation is caused by the twin gearstravelling around fixed ring gear 39, the cage 45 thereby rotating onits centerthe axis of shaft 14. Since there is a difference in ratiobetween gears 39 and 43 on the one hand and gears 41 and 44 on theother, the planetary movement of gear 44 induces rotation in ring gear41. The linear travel of the pitch circle of gear 44 is greater thanthat of the pitch circle of gear 43. Consequently, the gear 41 cannotremain stationary as is gear 39 but is rotated by gear 44 in thedirection of arrow 59--a direction opposite to the rotation of shaft 14.

Since the torque of motor 12 is the same on both the stator and therotor, but opposite, and the ultimate drive imparted to support 26 anddrum 11 is counter-clockwise as seen in Fig. 1, the elements 60 ofclutch 15 are arranged to lockthe drum to the shaft to prevent backup orbacklash of shaft 14.

In the capstan shown, assuming speed of rotation of the shaft at about2700-2800 R. P. M., the general proportions shown of the gears wouldresult in approximately l to 12 R. P. M. of the drum in the reversedirection from that of shaft 14.

The power advantage will be clear from the above, being in the nature ofone to more than two hundred. Consequently, a load on the end of a ropehaving one or more turns around the drum, will be easily but slowlypulled by said drum. The slope of face 30 causes a crowding of the turnsor convolutions of the rope and, thereby, creates friction between therope and drum surface 30 that minimizes slippage.

The modification of Figs. 4 and 5 has its power-advantage gear somewhatdifferently arranged in that the larger gear 44 of each twin gear is inmesh with the sun gear 42. In this form, the linear travel of the largerplanetary gear 44 is also greater than that of the smaller gear 43, asbefore. Actually, the only difference between the gearing of themodification and that of the earlier form is that the ratio betweengears 42 and 44 is greater in the modification than the ratio betweengears 42 and 43 in the earlier form. Therefore, the gearing of themoditication is the more powerful with a somewhat slowerV outputrotation of the drum.

The modification has the lateral extension 17 on its base instead of themeans 16. Said extension is shown with an aperture 61 that may beengaged by a hook or the reeve or the bight of a rope to renderthecapstan captive as to a tree or stump. Fig. 5 shows how a rope may betrained around drum 11 so that the end 62 may be held or restrained withlittle force while the drum is turned to pull a load on rope end 63.Reversely, the load may be payed out, as can be understood.

It will be noted that clutch 15 is mounted between drum 11 and the hub36 in the modification. Since said hub is stationary, the backlashfeature described above is effected.

While the foregoing has illustrated and described what are nowcontemplated to be the best modes of carrying out the invention, theconstructions are, of course, subject to modification without departingfrom the spirit and scope of the invention. It is, therefore, notdesired to'restrict the invention to the particular forms ofconstruction illustrated and described, but to cover :all rnodificationsthat may fall within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to besecured by LettersPatent is:

l. A caps'tan comprising a base,l a drum disposed above the base, ashaft disposed on the center of rotation of said drum and extending intothe base, an electric motor having a eld and an armature, the armatureof said electric motor being carried by the shaft and the eld of saidmotor being carried by the drum, a one-way clutch engaged with the drumto hold the latter against rotation in one direction an internal gearafiixed to the base on the axis of the shaft, a sun gear on said shaft,a planetary gear intermeshing between said internal gear and said sungear, a second internal gear carried by the drum above the fixed gear,and a second planetary gear fixed to and on the axis of rotation of thefirst planetary gear and in mesh with said second internal gear.

2. A capstan comprising a base, a drum'disposed above the base, a shaftdisposed on the center of rotation of said -drum and extending into thebase an electric motor having a field and an armature, the armature ofsaid electric motor being carried by the shaft and the field of saidmotor being carried by the drum, a one-way clutch engaged with the drumto hold the latter against rotation in one directionaninternal gearafiixed to the base on' the axis of the shaft, a sun gear on said shaft,a planetary gear intermeshing between said internal gear and saidV sungear, a second internal gear carried by thedrum above the fixed gear,and a second planetary gear fixed to and on the axis of rotation of thefirst planetary gearand in mesh with said second internal gear, the rstplanetary gear being smaller diametrally than the second planetary gearand the first internal gear being larger than the second internal gearin the ratio of size of the'plane` tary gears.

3. A capstan comprising a base, Ia drum disposed above the base, a shaftdisposed on the center of rotation of said drum and extending into thebase, an electric motor having a field and an armature, the armature ofsaid electric motor being carried by the shaft and the field of saidmotor being carried by the drum, a one-way clutch engaged with the drumto hold the latter against rotation in one direction an internal gearafiixed to the base on theV axis of the shaft, a sun gear on said shaft,a second internal gear carried by the drum above the fixed gear, andtwin planetary gears on a common axis of rotation, one of said planetarygears being in mesh with the sun gear and said latter gears being inmesh, one with the fixed internal gear and the other with the gear aixedto the drum.

4. A capstan comprising a base, a drum disposed above the base, a shaftdisposed on the center of rotation of said drum and extending into thebase, an electric motor having a field and an armature, the armature ofsaid electric motor being carried by the shaft and the field ofV saidmotor being carried by the drum, a one-way clutch engaged with the drumto hold the latter against rotation relative tothe shaft in onedirection an internal gear affixed to the base on the axis of the shaft,a sun gear on said shaft, a second internal gear carried by the-drumabove the fixed gear, and twin planetary gearsV on a common axis ofrotation, one of said planetary ge'arsbeing in mesh with the sun gearand said latter gears being in mesh, one with the fixed internal gearand the other with v the gear afiixed to the drum, the first planetarygear being 5. A capstan comprising a base, a drum disposed above thebase, a shaft disposed on the center of rotation of said drum andextending into the base, an electric motor havmg a field and anarmature, the armature or" said electric motor being carried by theshaft and the fieldof'said motor being carriedV by the drum, a one-wayclutch engaged with the drum to hold the latter against rotationrelative to the shaft in one direction an internaly gear afiixed to thebase on the axis of the shaft, a sun gear on said shaft, a secondinternal gear carried by the drum above the xed gear, and twin planetarygears on a common axis of rotation, one of said planetary gears being inmesh with the sun gear and said latter gears being in mesh, one with thefixed internal gear and the other with the gear `affixed to the drum,the planetary gear in mesh with the sun gear being larger diametrallythan the other planetary gear, and the internal gears being proportion'al to the difference in size of the planetary gears.

6. A capstan comprising a base provided with a fixed upwardly directedtubular extension, a drum around said extension and extendingthereabove, a fixed portion of said drum being disposed within saidtubular extension, anti-friction bearings between said portion of thedrum and the tubular extension, a motor-driven shaft extending centrallythrough said portion of the drum, planetary gearing interconnecting theshaft, drum and base to rotate said drum on said bearings and a one-wayclutch engaged with the drum to hold the latter against rotation in onedirection.

7. A capstan comprising a base provided with a fixed upwardly directedtubular extension, a drum around said extension and extendingthereabove, a fixed portion of said drum being disposed within saidtubular extension, anti-friction bearings between said portion of thedrum and the tubular extension, a motor-driven shaft extending centrallythrough said portion of the drum, planetary gearing interconnecting theshaft, drum and base to rotate said drum on said bearings, said basehaving a hollow boss formed therein, and said gearing being disposedwithin said boss and below the tubular extension of said base, #and aone-way clutch engaged with the drum to hold the latter against rotationrelative to the shaft in one direction, said clutch being disposedbetween said drum and shaft.

8. A capstan comprising a base provided with a fixed upwardly directedtubular extension, a drum around said extension and extendingthereabove, a xed portion of said drum being disposed within saidtubular extension, anti-friction bearings between said portion of thedrum and the tubular extension, a motor-driven shaft extending centrallythrough said portion of the drum, planetary gearing interconnecting theshaft, drum and base to rotate said drum on said bearings, said basehaving a hollow boss formed therein, and said gearing being disposedwithin said boss and below the tubular extension of said base, and aone-way clutch engaged with the drum to hold the latter against rotationin one direction, said clutch being disposed between said drum and saidbase.

9. A capstan according to claim 5 in which the base and the drum includeportions that cooperate to delne an interior space in which theplanetary gears are disposed and in which said gears move around theaxis of the shaft, a cage carrying said planetary gears, andantifriction bearings, above and below said gears, mounting the cage onthe shaft.

10. A capstan according to claim 5 in which the base and the druminclude portions that cooperate to dene an interior space in which theplanetary gears are disposed and in which said gears move around theaxis of the shaft, a cage carrying said planetaery gears, and comprisinga cage member on each side of said planetary gears, and an anti-frictionbearing mounting each cage member on the shaft above and below thegears.

References Cited in the file of this patent UNITED STATES PATENTS1,146,339 Matthews July 13, 1915 1,637,818 Hawkins Aug. 2, 19271,854,422 Osgood Apr. 19, 1932 2,363,093 Sprake Nov. 21, 1944 FOREIGNPATENTS 157,881 Australia Mar. 11, 1954

